Voice operated relay circuits



June 16,- 1931.

VOICE OPERATED RELAY CIRCUITS Filed June 6. 1929 TTRNEY J. L. HoGG1,810,016 C Patented June 16, 1931 UNITED STATES VJOHN L. Hose, or EASToRANGE, NEW JERSEY, Assrenon 'ro BELL TELEPHONE LAB- :PATENT vo1=1=1c1:

OR'ATQRIES,INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORKvoIcE OPERATED RELAY CIRCUITS Application led June 6,

This invention relates'to accelerating and vdelay action devices andmore particularly to relay karrangements suitable for controlling-signaloperated devices in signaling systems such, for example, as vo1ceoperated control vto insure proper operation ofthe circuit with `whichit is to be employed.

One lof the features of this invention consists in the method employedto secure rapid operationwithout contact chatter and to secure-aso-called hangover time inthe case of lsignal operated volume controlcircuits.

l The incoming signal `waves are rectied and these vrectified currentsare transmitted through the windings of a main and auxiliary relay.`iWhentheamplitude of the 'incoming impulses is sufficient to break thenormally7 closed contacts of the main and auxiliaryre- 4lays a batterycharges a condenser through fully operate.

other windings ofy each of the relays, thereby assisting the armaturestoward their operated positions andjcausing both relays to Atthe sametime a second condenser charges causing the grid of a three-elementvacuum tube to become more positive. The output ofthe vacuumtube isvtransmitted through another winding on thema-in relay which causes'thearmature of the main relayfto hold in its operated position. vAfter thecurrent from the rectifier approaches zero amplitude andthe first'condenser has fully charged, the armature of the auxiliary relayreleases and returns to its normal position.

This discharges the second condenser through high resistances,maintaining lthe main relay operated for a deiniteperiod of time whilethelsecond condenser is discharging.

The invention will be better yunderstood by referring to the followingdetailed descripv tion and accompanying drawings, wherein Fig. :1illustrates the preferred embodiment ofthe invention and'fliig. l-Aillustrates the same embodimentshowin the relays in schematic form tofacilitate fo lowing the descrip- "tion of the operation, oftheinvention.

y '1herelays and 2, which are preferably 1929. serial No.Y 368,955.

polar relays, and the equipment associated therewith are utilized tooperate switches,

ywhich complete an electrical path from conductor C to conductor C1v andopen the circuit through the normally closed electrical path` relay 1has windings 11, 13V and 15, andan armature 10, which armature is`arrangedto swing `between `'contacts `18V and 19. The .armature 1() isbiased by means of a spring `16 so that it is normally in connectionwith the contact 19. 1 y

The relay 2 has a yoke22 and av permanent magnet `24 associatedwith saidyoke. The relay 2 has windings 21and 23 and an armature which isarranged to swing between contacts 28 and 29. The armature 20 is biasedby means of a spring26` so that it is normally in connectionwith contact29.

The primary winding 4 of a transformer 3 is bridged across the line L.One end of the secondary winding 5 of transformer 3 is connected througha resistance 64 to the grid 62 of vacuum tube 6, and the other side ofthis secondary Winding 5 is connected to the filament 63 of vacuumtube-6. Plate 611of vacuum tube v6 isconnected through Winding 1 11 onrelay 1 and Winding 21 on relay `2 in series to the filament 63 ofvacuum tube 6. A condenser -is connected in series with winding 13 ofrelay` 1 and winding 23 of relay 2. A battery 32 and a resistance 31 areconnected in series with each other and in shunt with the vseriesconnection of the condenser 30 and the windings 13 and 23,` from thecondenser 30 to the winding 23. The grid 72 of vacuum tube 7 isconnected to the junction ofthe positive terminal of battery 32 andcondenser 30. The resistance 33 is connected between the filament 7 3.ofvacuum tube 7 and the junction of resistance31 and relay winding 23. Aresistance 35and a condenser 34 are connected in parallelV from the grid72 to the filament 73 of lvacuum tube 7. Winding 15 on relay 1 isconnected from the plate 71 to filament 7 3 of vacuum is normally inconnection with contact 29, is arranged to normally short-clircuit theseries connection of the condenser 30, Winding 13 on relay 1 and Windingon relay 2. The armature 20 is also arranged to .make connection withcontact 2S and thereby shortcircuit the resistance 33 when the armature2O is in its operated position.

rl`he operation et the system is as follows: The incoming` signalsreceived over the line L are transn'iitted through the transformer 3 tothe vacuum tu e rectifier G. The rectilied currents are transmitted fromthe filament 63 oi vacuum tube rectifier 6, through winding 21 on relay2 and Winding 11 on rela-y 1 to the plate 61 oi vacuum tube 6. Theserectified currents cause the armatures 10 and 2O of relays 1 and 2,respectively, to more 'from their normal position shown, therebydifconnecting the armature 19 iicm the contact 19 on relay 1 anddisconnecting the arn'lature 2O from the Contact 29 on relay 2.

lVhen the armature 2O is disconnected from contact 29 the condenserl 30charges up through the circuit from battery 32, condenser 30, Winding onrelay 1, winding 23 on relay 2, resistance 81 to bi ttery The chargingcurrent which flows through Winding 13 on relay 1 and Winding 28 onrelay 2 assists the rectified current from the output of vacuum tuberectifier 6 in moving; the armatures 19 and 2O toward their operatedpositions, thereby completely operating these relays 1 and 2.

At the same time, the condenser Sil is charged through the circuit frombattery 32, resistance 31, resistance 33, condenser 3ft to battery Theresistance 33 causes condenser 341 to charge more slowly than condenser30. As condenser 3ft charges the grid 72 of vacuum tube 7 becomes morepositive with respect te the iilament 73.

A s soon as the armature 2O on relay 2 reaches contact 2S the resistance33 is shortcircuited which causes conuenser to charge more rapidly andincreases the positive potential oi the grid 2'2 of vacuum tube 7. Asthe grid 72 becomes more positive, the space current irom the lilament73 through ninding 15 on relay 1 to the plate 71 of vacuum tube 7increases, thereby causing the arma-- ture 10 on relay 1 to hold in itsoperated position after the cessation of signal impulses from the lineL.

After the signal currents from the line L have approached Zero amplitudeand the condenser 30 has :iully charged, the armature 2O on relay 2 isreleased and returns to its normal position shown. As soon as armature2O disconnects from contact 28, condenser 34 begins to discharge throughresista-nce 35. As soon as armature 20 meets Contact 29, the condenser34; discharges through the circuit from condenser Sil, resistanee 33,armature 20, contact 29 to condenser 34 in addition to the circuitthrough resistance 35. As resistances 33 and are preferably large, thespace current from vacuum tube 7 which flows through winding 15 on relay1 is maintained suiliciently large to hold the armature 10 of relay 1 inan operated position for a denite period oi time While the condenser 34is discharging.

The connection of armature 2O with contact 29 also causes the condenser89 to discharge through the circuit from condenser 80, Winding 13 onrelay 1, Winding 23 on relay 2, armature 2O and contact 29 to condenser30. This condenser discharge current tends to hold the armature 2O onrelay 2 in its normal position Without contact chattering` taking placebetween the armature 2O and the contact 29. This condenser dischargecurrent also tends to cause the armature 10 of relay 1 to leave itsoperated position but as the discharge current through Winding 13 ispreferably made smaller than the holding current through Winding 15 onrelay 1, the armature 10 Will remain in its operated position for adefinite period of time While the condenser 34; is discharging.

When the next impulse is transmitted over the line L the current throughthe Winding 21 on relay 2 will again move the armature 2O to itsoperated position, thereby causingr the armature 20 to again disconnectfrom contact 29 and make connection with contact 2S which again chargescondensers 30 and 34 as is described above.

In this manner the electrical path from conductor C through theconductor C1 is maintained operated and the electrical path fromconductor C through the conductor (lJ is maintained disabled as long asimpulses are transmitted over the line L in sufliciently short recurringintervals.

When the condenser 34 discharges before a succeeding impulse is receivedover the line L, the armature 10 on relay 1 will return to its normalposition under control of the biasing means, thereby opening the pathfrom conductor C to conductor Cl and closing' the path from conductor Cto conductor C2.

The invention is also capable of other modiiications and adaptations notspecifically rf ferred to but included Within the scope of the appendedclaims.

Vhat is claimed is:

1. In an electrical communication system over which signal currentimpulses are transmitted, a main relay and an auxiliary relay. means forinitially energizing said main and auxiliary relays by said currentimpulses, means including a condenser for further energizing said mainand auxiliary relays, means including a three-element thermionicdischarge device for still further energizinn said main rela-y, meansfor releasing said auxiliary relay at the cessation of said sigllt iso

nal current impulses, and a slow electrical circuit comprisingcapacitance connected between the grid and filament of said thermionicdischarge device and high resistances connected to said capacitance, toprevent the release of said main relay for a predetermined time aftersaid signal current impulses have ceased.

2. A delay action device comprising avmain relay and an auxiliary relay,a winding on each of said relays, said windings con nected in series toa source of electrical impulses, a condenser connected in series withother windings on each of said relays, a source of potential and aresistance connected in series across the series connection of saidcondenser and said other windings a three-element vacuum tube, theoutput of which is connected in series with a third winding on said mainrelay, another condenser and another resistance connected in parallelacross the input of said vacuum tube, connections from said, source ofpotential to said other condenser, a normally closed contact on saidauxiliary relay, and connections from said normally closed contact tosaid condensers Jfor discharging said condensers when said contact isclosed.

3. A polar relay circuit including a main polar relay and an auxiliarypolar relay, said main polar relay having an armature, a pair ofcontacts between which said armature is adapted to swing, an operatingwinding, an accelerating winding and a holding winding associated withsaid armature, said auxiliary polar relay having an armature, a pair ofcontacts between which said armature is adapted to swing, biasing meansassociated with said armature to maintain said armature normally inconnection with one of said contacts, and operating winding and anaccelerating winding associated with said armature, said acceleratingwindings on said main and said auxiliary relays bridged across thearmature and the contact normally in connection Y with said armature onsaid auxiliary relay, means for energizing said accelerating windings tosupplement the action of said operating windings on said main andauxiliary relays when said normally closed contact on said auxiliaryrelay is opened, a three-element vacuum tube arranged to transmitcurrent through said holding winding on said main relay when saidnormally closed contact on said auxiliary relay is open and a slowelectrical circuit connected to the input of said vacuum tube to preventthe cessation of current in the output circuit of said vacuum tube for apredetermined time after said auxiliary relay has released.

4. In a relay circuit for operating and holding a relay operated undercontrol of impulses, a space discharge device in circuit lwith a windingon said relay, a condenser controlling by its potential the ilow ofcurrent through said space discharge device and hence through saidwinding, means operated in response to'said impulses for assisting inthe initial operation of said relay and altering the charge in saidcondenser in a direction to increase current low through said dischargedevice to cause operation of said relay, and Vcircuit connectionscontrolled by said means in response to said impulses for altering thecondenser charge in the reverse direction too slowly to permit releaseof the relay during a succession of said impulses.

5. In a relay circuit for operating and holding a relay operated undercontrol of impulses, a winding on said relay connected to the source ofimpulses, a space discharge device in circuit with another winding onsaid relay, a condenser controlling by its potential the flow of currentthrough said space discharge device and hence through said otherwinding, means operated in response to said impulses for assisting inthe initial operation of said relay and altering the charge in saidcondenser in a direction to increase current llow through said dischargeVdevice to cause operation of said relay, and

circuit connections controlled by said means in response to saidimpulses for altering the condenser charge in the reverse direction tooslowly to permit release of the relay during a succession of saidimpulses.

6. In a relay circuit for operating and holding a relay operated undercontrol of impulses, a winding on said relay connected to the source ofimpulses, a space discharge device in circuit with another winding onsaid relay, a condenser controlling by its potential the flow of currentthrough said space discharge device and hence through said otherwinding, means operated in response to said impulses for assisting inthe initial operation of said relay and altering the charge in saidcondenser in a direction to increase current flow through said dischargedevice to cause operation of said relay, and circuit connectionscontrolled by said means in response to said impulses for altering thecondenser charge in the reverse direction too slowly to permit releaseof the relay during a succession of said impulses, said last mentionedmeans comprising a relay having two windings, one of saidlast mentionedwindings being connected in series with said first mentioned winding onsaid irstmentioned relay.

In witness whereof, I hereunto subscribe my name this 3rd day of June,1929.

JOHN L. HOGG.

